The invention relates generally to doors, and more specifically, to method of making metal clad doors having a foam or polystyrene core with seamless edges.
Doors having a foam or polystyrene core with an outer cladding of metal, such as steel, are known. Conventionally, these doors are constructed by enclosing the polystyrene door in the metal sheeting. The metal sheeting comprises a front metal sheet and a back metal sheet, the sheets commonly referred to as door blanks. The door blanks abut where they are wrapped or folded around the peripheral edges of the door, leaving a seam or gap between the two blanks along the peripheral edges of the door. In most instances, to make a door that appears seamless along the edges, the seam is spot welded at six (6) to twelve (12) inch intervals to secure the sheets around the door at the peripheral edge. Spot welding is used because the polystyrene melts under the high heat that would be required to run a weld bead along the entire length of the seam. Once the seam is spot welded, the seam then is filled with a filler material or putty, such as Bondo® (3M) or other appropriate material. The filled seam is sanded and the door is painted. This process is time consuming and can take about 30 to 40 minutes or more per door. The quality and aesthetic appearance of the seamless edge can vary depending upon the filling and sanding steps.
It would be advantageous, therefore, to have a method of manufacturing a steel clad door with a polystyrene core that has an improved seam weld that will not melt the polystyrene core and improves the fit and finish of the door having seamless peripheral edges.